Cubase Pro 9.5 collaboration help please

In these days of lock down my band mate and I wanted to use cubase to record a few ideas remotely. We have tried but get in a real mess and seem unable to save, mail, add to the project and mail it back etc.
Is there a process I can follow please to exchange work on a project remotely from each other.
Any help appreciated. Thanks.

How exactly are you unable to do that? If you don´t know how to mail projects, it will not work.

Currently i set up a new cubase project file.
then use a pre set template and maybe add a midi drum track and a guitar track
Next step I save in the new projext folder
I then go and use Win rar to compress the .cpr and and .csh files in that folder and e-mail to my friend.

Seems when he then opens it and loads it into his cubase there are then files missing, eg guitar audio track is missing

Not sure who of the two of us doing the wrong thing.

Probably you are doing something wrong.
The project folder is usually the place where the recorded audio files are saved in. It is set before creating the project. If you create a new folder tom save the project file in, this will not copy the audio files to the new folder. If you want to create a new project folder with all the audio files in it, finish your additions, and use the “backup project function” and tick the appropriate options. That will copy all the audio files to the folder, MIDI data is included in the project file.

Thank you very much, that is making more sense now, much appreciated .